This study involves kinetic investigations of transalkylations from S-adenosylmethionine (enzymic), or less complex sulfonium compounds (non-enzymic) to a variety of nucleophilic acceptors. These data are used to design inhibitors of several transalkylases involved in methyl transfer and polyamine biosynthesis. These new drugs are studied in several cell-free systems as well as in mammalian cell culture systems. BIBLIOGRAPHIC REFERENCES: Richard W. Stout, Arlene R. Cashmore, James K. Coward, Czaba G. Horvath, and Joseph R. Bertino. Separation of Substituted Pteroyl Monoglutamates and Pteroyl Oligo-lambda-L-glutamates by High Pressure Liquid Chromatography. Anal. Biochem., 71, 119 (1976). Roger Lok, and James K. Coward. Steric Constraints in Intramolecular Reactions at sp3 Carbon. Implications for Methylase Mechanisms. Bioorg. Chem., 5, 169 (1976).